Fischer projection formulas for the D-aldose family (three to six-carbon atoms) are shown below. Asymmetric carbons are colored red. The L-family of aldoses are the mirror images of these structures.
A very nice Carbohydrate Site has been created and maintained at Leeds.

Most of the aldoses shown above exist chiefly as five and/or six-membered cyclic hemiacetals. The five-membered hemiacetals are classified as furanoses, and the six-membered analogs as pyranoses. The following diagram shows how glucose forms a glucopyranose structure. Since a new asymmetric center is generated in this cyclization, two new stereoisomers, termed anomers and designated a and b, are formed. The new stereocenter is termed the anomeric carbon, and is colored red in the formulas shown here. The cyclic forms are often displayed in a flat projection known as a Haworth formula, or more accurately, as a puckered (eg. chair) conformation.

Models of glucose, galactose, mannose and allose pyranose structures may be viewed by clicking Here. Note that this feature requires the CHIME plugin for complete viewing.

Organic Chemistry
Michigan State University